Printed labels are widely used on containers to identify the particular products, manufacturers, and brand names associated with the products in those containers. Conventional labels for containers include labels facestocks made from paper, films, and other polymeric materials. Paper-based labels typically have an opaque appearance, whereby the contents of the container are at least partially concealed from view. While paper-based labels are generally inexpensive, they are susceptible to damage, such as by abrasion or scuffing and generally exhibit poor adhesion in wet or humid environments. Opaque labels have also been made from polymeric materials, including thin films. While these materials offer improved resistance to scuffing and abrasion, as well as improved adhesion in humid conditions, opaque polymeric labels also conceal at least a portion of the product held within the container.
A recent trend in labeling containers has been towards utilizing clear thin film labels which provide a “label-less” or “printed-on” look. These labels have the advantages of improved resistance to scuffing and abrasion, and good adhesion in moist environments, and further provide improved aesthetic appearance of the containers to which they are applied. Both paper-based and polymeric labels are commonly imprinted with various graphics and text which may be applied to the labels by various methods including gravure printing, lithography, flexography, screen printing, and other methods suitable for creating the desired indicia on the labels.
Container labels described above have typically been provided in “cut-and-stack” form or roll form for application to containers by automated labeling equipment. In the cut-and-stack form, a plurality of individual labels are provided in a stack to a labeling machine, generally in a magazine, whereby the machine is configured to apply individual labels from the stack to containers as they are moved past a labeling station. The cut-and-stack labels may be provided with a pre-applied adhesive for securing the label to the containers, or the adhesive may be applied by the labeling machine immediately prior to affixing the label to the container. This method of supplying and applying labels to product containers has generally been utilized with paper-based labels.
Labels may also be provided in roll form wherein a plurality of discrete labels are provided on an elongate web of backing material that has been wound into a roll. The web of backing material is directed past a peel tip at a labeling station to transfer the label from the backing material to the individual product containers. This method of supplying labels to containers has typically been utilized with thin film and other polymeric labels. Adhesive is generally pre-applied to the labels and may be pressure sensitive or heat activated to adhere to the containers.
Polymeric labels, including thin film labels, have generally not been provided in cut-and-stack form due to various difficulties associated with providing polymeric labels in a stacked form. In particular, the polymeric materials are susceptible to developing static charges which cause the individual labels to cling to one another and to the labeling equipment, thereby hindering accurate and repeatable application of the labels to the product containers. Another factor which has hindered the provision of polymeric labels in stack form is that adhesives used in conventional cut-and-stack applications do not work well with polymeric materials. Furthermore, conventional cut-and-stack adhesives are not transparent. This is particularly problematic when the polymeric materials are transparent because the adhesives may be visible through the transparent label, thereby depreciating the aesthetic affects.
Labels provided to labeling equipment in cut-and-stack form may advantageously be applied to individual containers at very high rates, such as 1200 labels per minute or more. These high application rates are well suited for use with high-speed packaging lines. While the costs of polymeric labels, including thin film labels, has been gradually decreasing, paper-based labels are generally considered to be the least expensive labeling material. On the other hand, the polymeric-based labels, particularly clear, thin film labels, are generally associated with improved product appearance.
There is thus a need for a product label which provides improved aesthetic appearance, while being economically competitive to paper-based labels and capable of application to products in high speed manufacturing lines.